When Talkin’ Birds Senior Producer Debbie Blicher was in fourth grade, her class was challenged to design a vehicle that would allow an egg to survive a two-story drop without cracking. She and her partner had both watched birds build nests, so they cradled their egg in loosely packed, shredded paper—a sort of spherical nest—inside a paper lunch bag (even then, Debbie recycled!). Theirs was the only egg that survived the drop.

In view of this triumph, Debbie is pleased to learn that Dr. Hunter King, a University of Akron experimental soft matter physicist and assistant professor of polymer science and biology, has received a three-year, $260,000 grant from the National Science Foundation’s (NSF) Division of Civil, Mechanical and Manufacturing Innovation to study “the collective mechanical interactions of disordered, randomly packed elastic filaments.” In other words, twigs packed together. In other, other words: birds’ nests.

Birds’ nests have to withstand weather changes, swaying trees, repeated impact from birds sitting on or entering them, and other mechanical factors—all without damaging the eggs they contain. As King puts it, “Nests are lightweight, soft, flexible and shock-absorbent, but made up of hard, durable components – properties which are ideal for packaging materials.”

In the abstract submitted to the NSF, King and his collaborators from the University of Illinois at Urbana-Champaign (Illinois) state that they’re investigating how birds’ nests hold their shape as a “result of a subtle interplay between geometry, elasticity and friction” and point out that this question has not yet been thoroughly studied.

King’s graduate assistant Nicholas Weiner is conducting a series of experiments to analyze the behavior of randomly packed filaments in response to various perturbations. The collaborators at Illinois will attempt to duplicate his findings through computer simulations

Understanding how nests work could fuel advances in civil engineering and architecture, among other disciplines—not to mention packaging.

King plans to collaborate with the Akron Zoo to set up cameras and record birds building their nests: the original engineers at work.

So the next time a kid you know is participating in the “egg drop” challenge, think of birds nests and Dr. Hunter. And who knows? Maybe the kid will grow up to get an NSF grant. (Or to be Talkin’ Birds Senior Producer.)

As human population increases, we need more food. To increase food production, we often claim wild grassland and make it into farmland, which means treating it with pesticides, fertilizers, or both. When we treat the land, insect populations diminish and become less diverse, which affects all animals that feed on those insects—including birds. In fact, aerial insectivores—birds that hunt for insects on the wing—are declining across North America. A forthcoming study in The Condor: Ornithological Applications takes a closer look at precisely how Tree Swallows are affected by agricultural practices.

In 2012 and 2013, Chantel Michelson, Robert Clark, and Christy Morrissey—all researchers at the University of Saskatchewan—monitored Tree Swallow nest boxes at agricultural and grassland sites. To find out what the birds were eating, they collected blood samples and measured isotope ratios. (Measuring certain chemical elements in tissues is an established way to glean diet data.) Tree Swallows usually eat aquatic insects. Since water receives pesticide runoff, the researchers expected that the swallows living near cropland would be forced to eat more land-based insects than the swallows living near wild grassland.

What the researchers found surprised them. The Tree Swallows at both locations ate more aquatic insects than expected. In fact, in 2012 the birds at agricultural sites ate more aquatic insects than the birds at the wild sites. In other words, even though the agricultural sites had been treated for farming, the swallows still preferred the insects there to the insects living by the water. The researchers think this might mean that wetlands provide some cushion for birds against changes brought about by farming.

One other surprising finding: The swallows living at agricultural sites weighed less than the swallows living in wild grassland. They were healthy, just smaller, which might mean they had a harder time finding food. But in both locations, adult swallows seemed to rely on aquatic insects for themselves and their young, illustrating the importance of wetlands for bird survival.

As you may know, the Common Cuckoo and Oriental Cuckoo are brood parasites. That is, they lay their eggs in the nests of other birds, leaving their chicks to be raised by the unsuspecting foster parents. A cuckoo chick in the nest reduces the likelihood that the original chicks will survive, because female cuckoos time their egg-laying so that their chicks hatch first...and then shove the other eggs out of the nest.

In areas where brood parasites are common, host species often develop coping strategies. Some birds hide their nests, or nest at different times. Some attack the brood parasite before she lays her egg or abandon the nest once she's laid it. Others pierce the parasite's egg and toss it out of the nest.

But what about birds that live where brood parasites aren't common? A new study from the University of Illinois and the University of Tennessee, Knoxville shows that an invasion of cuckoos from eastern Russia might cause significant losses among Alaskan birds. Professors Mark Hauber and Vladimir Dinets led the study to learn what Alaskan birds do—or don't—know about coping with brood parasites.

Common Cuckoos and Oriental Cuckoos are occasionally sighted in Alaska. Most likely, they've gotten there from Beringia in eastern Russia. While there isn't solid evidence that cuckoos are breeding in Alaska, Hauber says "it's likely already occurring."

Researchers put two types of fake eggs into the nests of more than two dozen songbird species in both Siberia and Alaska. (The fake eggs resembled varieties of cuckoo eggs.) Common Cuckoos and Oriental Cuckoos have advanced into Siberia and now breed near the Bering Strait; in comparison, Alaska is new territory. The researchers made sure to test each nest with each kind of egg. After the usual losses from predation, they had data from 62 nests of 27 bird species.

Fourteen out of 22 Siberian nesting pairs rejected the fake eggs, but only a single one of the 96 Alaskan pairs rejected the fakes. Hauber suspects this result indicates that Siberian songbirds have encountered cuckoos long enough to develop coping behaviors, but he's worried about Alaskan songbirds. "The North American hosts have no defenses against invading cuckoos. They will be parasitized."

We hope that future ornithologists will follow up to find out how the Alaskan songbird population distribution has changed—and whether any of them have wised up about cuckoos.

When the Australian floodplains fill with water, wetland birds gather there to mate. But when the wetlands dry up, where do the birds go, and what’s it like there?

There are the questions asked by Dr. Kate Brandis, a research fellow at the University of New South Wales’s Center for Ecosystem Science. To answer them, she has turned to a surprising source: feathers.

In Australia, banding birds hasn’t worked well. The birds that would be most useful to track have a high mortality rate, and many bird species live in areas where they are simply too difficult to catch for banding. So, two years ago, Dr. Brandis embarked on a citizen science project to help her understand where wetland birds hang out when they’re not breeding and whether they’re getting what they need there.

Dr. Brandis sent out a public call for people to mail her feathers of wetland birds along with records of where they were found. She has received thousands of feathers from about 480 locations across Australia.

Back in the lab, Dr. Brandis’s team analyzes each feather for evidence of its former owner’s history. Feathers are made of a protein called keratin—which is present in most animals’ hair and nails, including ours. Keratin from a small section of feather can yield information about what its owner ate while that feather was in use. Chicks tend to grow up in one place, so their feathers provide a good picture of the diet available in a single wetland. The feathers of older birds can be compared against these known locations to show which wetlands a bird visited and how healthy those places were.

When Dr. Brandis releases her results, they will help bring unhealthy wetlands to the attention of managers. Since 1971, 65 Australian wetlands have been designated as “significant” under an international conservation treaty known as the Ramsar Convention. As Dr. Brandis explains, her feather data “[will put] even more pressure on wetland managers to get it right.”

Do you have a feather you’d like to send? Would you like to know more about this study? Click here!

When we call someone "bird-brained," we might be right. New research indicates that the brains of birds, primates, and even some reptiles may have evolved from cells that started out the same.

In mammals, the outer layer of the brain—called the neocortex—is where most higher-order processing happens. When we move, use spatial reasoning, or speak, we're using our neocortex. In birds, a region of the brain known as the dorsal ventricular ridge, or DVR, is responsible for higher-order processing. But rather than being a thin layer on the brain's surface, it consists of clusters of cells called nodes. The avian DVR is so different from the mammalian neocortex that scientists figured that there was little relationship between them, if any.

Odd as it may seem, embryos of most vertebrate species start out looking similar. Birds, primates, reptiles--anything with a spine--all look alike in the early stages of development. Now, new research from the University of Chicago indicates that some of the cells in the neocortex and the DVR start out as the same kind of cell, growing in the same region of the embryonic brain. (This means that, before each of us was born, we had brain cells that could have grown up to belong to birds.) (Or, if you're Ray, maybe they actually did!)

In 2012, Dr. Clifton Ragsdale and his team of researchers at the University of Chicago discovered that certain genetic markers in brain cells of the mammalian neocortex matched with genes in the cells of several bird DVRs. A new study at Ragsdale's lab, led by graduate student Steven Briscoe, found that other neurons in the DVR share molecular signatures with a kind of communication cell in the neocortex called an IT neuron. These IT neurons help the neocortex communicate among its various layers and from one side of the brain to the other.

"The structure of the avian DVR looks nothing like the mammalian neocortex, and this has historically been a huge problem in comparative neuroscience," Briscoe explains. "Our identification of IT neurons in the bird DVR helps to explain how such different brain structures can give rise to similar behaviors."

Dr. Ragsdale sums up the study this way: "What this research shows is that [birds are] using the same cell types with the same kinds of connections we see in the neocortex, but with a very different kind of organization."

In fact, it suggests the possibility that birds and primates evolved intelligence independently, starting with the same cell types and developing different brain structures.

A new study in Proceedings of the National Academy of Sciences indicates that birds respond like humans do when exposed to constant loud noise. Researchers found that adults and nestlings of three species in the wild showed signs of chronic stress caused by human noise pollution.

Most birds exposed to constant loud noise will simply leave an area; this study looked at what happens to the birds that stay. Lead author Nathan Kleist conducted the research while a Ph.D student in evolutionary biology at the University of Colorado-Boulder, along with co-author Rob Guralnick, associate curator of biodiversity informatics at the Florida Museum of Natural History.

The research team, led by Kleist, set up 240 nesting boxes at three specific distances from gas compressors on property in New Mexico. The team tested levels of the stress hormone corticosterone in three species: Western Bluebird, Mountain Bluebird, and Ash-throated Flycatcher. The researchers found that the louder the noise from the gas compressors, the lower the birds’ baseline corticosterone levels in all three species.

Christopher Lowry, study co-author and stress physiologist at CU Boulder, explains: Although it seems odd that the corticosteroid levels would be low, lab studies of chronic stress in humans have shown that low corticosterone can signal stress so intense that the body has to reduce baseline levels of the hormone to protect itself (so that there's room for it to shoot up if needed). In fact, when these birds experienced sudden stress, their corticosteroid shot up high and came down only very slowly, like it does in chronically stressed humans.

In the noisiest environments—the ones closest to the compressors—nestlings had smaller body size and reduced feather development. In Western Bluebirds, the species that showed the greatest noise tolerance, fewer eggs hatched than expected.

“These birds can’t escape this noise," says Guralnick. "It’s persistent, and it completely screws up their ability to get cues from the environment." For example, adults rearing chicks can't tell whether it's safe to leave the nest for food. Guralnick explains, "Just as constant stress tends to degrade many aspects of a person’s health, this ultimately has a whole cascade of effects on their physiological health and fitness.”

Since noise at natural gas fields is not unusually loud compared with human noise in many other parts of the country, this study has implications for protecting wildlife and even human health. The researchers suspect that if other species react the way these species did, bird populations could decline if we humans become noisier.

“This study shows that noise pollution reduces animal habitat and directly influences their fitness and ultimately their numbers,” Guralnick said. “By doing so, it makes it harder for animals to survive. Taken together, that’s a pretty damning picture of what human-made noise can do to natural populations of animals.”

If you live in North America and you love the European Starling, most folks say you can credit Eugene Shieffelin. If you hate the European Starling, they say you can blame the same guy. It's Shieffelin who is largely credited with introducing 60 starlings to New York City's Central Park in the year 1890 and another 40 in 1891. As we all know, they thrived. And thrived. Today, they number around 200 million in North America, with a range all across the continent, and are considered one of the most invasive species on the planet. So if you love them, you can thank Mr. Shieffelin for the huge flocks of noisy, speckled black birds.

Shieffelin didn't act alone, however. He belonged to the American Acclimatization Society, an organization founded in New York City in 1871 whose goal was to introduce to North America useful species from other countries. In retrospect, we 21st-century types think "useful" was defined rather loosely. After all, the starling isn't especially useful—unless, as is rumored about Shieffelin, you have such a thing for the birds of Shakespeare that you want them all to live right near you. (There actually is not much evidence for this popular story.)

So how did the American Acclimatization Society come to be? Well, for that we can blame the Société zoologique d'acclimatation, founded in Paris in 1854 by naturalist Isidore Geoffroy Saint-Hilaire. He encouraged the French government to import and breed species that would help feed France and control pests. He encouraged other countries to start similar chapters.

By 1877, the American Acclimatization Society was going strong, and Shieffelin, a drug manufacturer from the Bronx, was its chairman. We imagine he must have thought, "How pretty those starlings are! How intelligent and entertaining! What harm could they do?" What harm indeed! They have crowded out countless native North American bird species, interfered with agriculture, and even been a primary cause of airplane bird strikes.

Some bad ideas that seem fun at the time are pretty harmless, such as shaving half your beard or adding extra hot pepper to your chili. But importing non-native species? Not harmless. So let's enjoy European Starlings, but let's also try to educate humankind about invasive species so we don't make such mistakes in the future. The fault? Quite simply, it's ours.

In recent years, we've seen well-documented declines in domesticated honey bees, monarch butterflies, and other insects that attract a lot of attention. But we haven't really noticed the moths, beetles, and other insects that flitter and crawl through our everyday life. Birds, however, probably notice their decline a lot, since they're a major food source.

A recent story in the journal Science documents a new set of data gathered mostly by amateur entomologists in western Europe. These folks have tracked insect abundance at more than 100 nature reserves since the 1980s, and the news is not good.

This group of amateurs, named the Krefeld Entomological Society (after their location in Germany) has seen the insect catches in their traps fluctuate every year. This is normal. But in 2013, they noticed that one of their longest-running sites showed a decline by mass of almost 80%. The numbers were just as low in 2014. In fact, the group found dramatic declines across more than a dozen other sites, even in reserves where plant diversity and abundance had improved.

The group has installed more traps each year since 2013. They've also begun working with university-based researchers to look for correlations with weather, changes in vegetation, and other factors. Unfortunately, no simple cause for the decline has yet emerged.

If you don't like bugs, you're probably asking, "Why does this research matter?" The answer is that other creatures eat insects—such as birds. Dave Goulson, an ecologist at the University of Sussex in the United Kingdom, explains, "If you're an insect-eating bird living in that area, four-fifths of your food is gone in the last quarter-century." No matter what your opinion of bugs, this is important news.

No one knows what this research in western Europe means for insects elsewhere. But we at Talkin' Birds think that anything that affects the food chain for birds anywhere is worth investigating for the good of us all.

The Connecticut Warbler was our Featured Feathered Friend on a recent show. We described it; pointed out how a Sean Connery character misidentified it in a major motion picture (Finding Forrester); and talked about the fact that the bird is named for a state where it’s not often found. But we’ve since learned something new and amazing about the Connecticut Warbler, thanks to a story in the August issue of BirdWatching Magazine. The story quotes bird biologist Emily McKinnon about new evidence that the Connecticut accomplishes feats of migratory flight similar to those of the Blackpoll Warbler, which is a North American migration champion. The new research shows that, like the Blackpoll, the Connecticut Warbler travels long distances non-stop over the Atlantic Ocean on its journey to its South American wintering grounds, flying for at least 48 straight hours over the bounding main—and that’s only part of the trip! Check out the article for all the details.

Before you get worried, we'd like you to know that no owls are harmed in the making of fine California wines. In fact, they get paid well — in rodents.

Rodents like to eat grape vines, and Barn Owls like to eat rodents. Many Napa Valley wineries control rodents by putting up nest boxes to establish Barn Owl populations. Researcher Sara Kross from the University of California Davis says that more than 99% of prey items in barn owls’ diets on the farms she studied were agricultural pests — mice, voles, and pocket gophers. Fewer of these pests means easier growing for grapevines.

Welcoming Barn Owls allows wineries to reduce or eliminate the use of rodent poisons. It's important to note that, if poisons must be used, they should be used with care, since an owl that eats a poisoned critter will ingest the poison, too.

The American Bird Conservancy reports that an international team of researchers has solved one of South America's great bird mysteries: that of the elusive Táchira Antpitta. It's a small, brown bird that had not been seen since the 1950s, listed as Critically Endangered and even thought to have gone extinct.

Antpittas are reclusive birds that are easier heard than seen. Unfortunately, the team had no sound recordings, so no one knew what to listen for. They did know where to search for it, though. Eventually, they picked up the distinctive sound of an antpitta that they had never heard before, deep in the mountainous forests of western Venezuela, and were then able to identify the bird from previous descriptions.

Similar habitat can be found nearby in Colombia, and the scientists think the species might also occur there. They’re now working to determine the bird’s full range and habitat requirements, and how best to ensure its continued survival.

Here are some starter facts. Flower preferred by bees ("bee" floral variants) tend to be upright and have blue or purple coloration, since bees have trouble seeing the color red. "Bird" variants, meanwhile, tend to be horizontal with red or orange coloration. Also, bee flowers yield small amounts of concentrated nectar, while bird flowers give pollinators larger amounts of dilute nectar.

Robert Gegear, assistant professor of biology and biotechnology at Worcester Polytechnic Institute (WPI), wanted to understand how flower characteristics combine to influence the decisions bumblebees make about which flowers to visit. In other words, What kinds of flowers encourage or confuse bees?

For the first step of the study, Gegear and his team of students trained bees to forage on arrays of paper flowers that all had the same color, orientation, and type of nectar reward. The bees learned that every color and orientation combination yielded the same reward.

The team then gave the bees arrays in which flowers of one color/orientation combination contained nectar and the other combinations contained distilled water. Gegear and his students recorded how long it took the bees to learn which flowers were worth visiting.

The bees took longer to learn about certain combinations than about other combinations. That is, fake flowers that would favor birds in real life were more confusing for bees than fake flowers that would be better for bees in real life.

Why? Gegear explains, "These data suggest that the reason bee-to-bird evolutionary transitions are often accompanied by a floral shift to classic 'bird' trait complexes is because bees have a particularly difficult time combining red with other sensory traits, including nectar rewards." In other words, bees have a hard time recognizing red flowers, so any trait associated with red flowers is not worth their time to learn, even if learning would mean a greater nectar reward.

Then where do hummingbirds come in? Well, if bees tend to ignore flowers that are difficult for them, then other pollinators, such as hummingbirds, make their move. Gegear says, "In the case of the two species of Mimulus, the costs associated with bird combinations are much greater than the costs associated with bee combinations, so bees avoid them to increase their foraging efficiency....When you put all this together, you find that 'bird flowers' are really 'anti-bee flowers' that function by exploiting specific sensory and cognitive limitations." That is, hummingbirds forage where bees don't bother to forage.

Like most pollinators, bees are not genetically programmed to visit only particular flowers; instead, they seek to gather the most nectar in the least time however they can. In other words, they're generalists. From the plant's perspective, however, the best pollinator is a specialist in that plant. (Think of a building toy, like Lego, that clicks only with itself, which forces shoppers to buy only that one brand of building toy.) By combining particular floral characteristics, plants manipulate pollinators to become specialists because generalizing becomes a waste of time. In Gegear's words, "From an ecological perspective, an ideal pollinator is one that always forages on flowers of the same type so pollen is transferred effectively. In reality, pollinators are generalists and they should simply forage randomly. So the big question has been, how do plants get the pollinators to do what they want?"

Gegear suggests that most hummingbird-pollinated flowers once had bee-pollinated ancestors. He says his study shows that at least two floral characteristics had to change for the bird flower Mimulus cardinalis to evolve from the bee flower Mimulus lewisii, and that those changes served to discourage bees.

Regardless of the flower, we can be kind to pollinators by avoiding pesticides in our gardens and by providing shelter and water for pollinators.

A team of researchers in New Hampshire and Maine are investigating whether birds move into land that has been cleared along the route of a power line or has recently been logged. “Our goal is to get a better understanding for how these habitats function in our landscape,” says wildlife specialist Matt Tarr of the University of New Hampshire Cooperative Extension.

The study is being funded by the federal Natural Resources Conservation Service. A more controversial source is the National Fish and Wildlife Foundation’s New England Forests and Rivers Fund, to which the utility Eversource is a contributor. The controversy is that Eversource has proposed the Northern Pass energy transmission project, which entails building a 192-mile electricity transmission line from Pittsburg to Deerfield, New Hampshire. Property owners and tourism officials, among others, have criticized the project.

Tarr explains that the study isn’t intended to find benefits in building a transmission line. Rather, it's to help determine how birds use the forests that emerge after such a project is built. Tarr's research could help inform policymakers as they work to create more young forests for birds and other species. It will focus on 24 transmission line rights-of-way and 12 logged areas in southeastern New Hampshire and southern Maine. “We might find these rights of way aren’t used as we think they are for mature forest birds," explains Tarr. "That would be important for us to know.”

Starting in late May, Tarr and his colleagues will catch songbirds and band them, then track them over the next two years. Tarr says as many as 40 songbird species nest in young forests, and another group nests in mature forests. Additional evidence suggests young birds that have just left the nest will often live in young forests while their development finishes. In some parts of the country, these younger forests have been found to provide food sources and protection for birds.

We here at Talkin' Birds are all for the peaceful coexistence of humans with birds and other creatures. We appreciate careful research that leads to wise decisions. We wish Matt Tarr and his team good luck and clear results.

People better at birding by ear than by eye can find it maddening to try to hear songs and calls over traffic noise. We wait for the bird to raise its voice once the rattling trucks have passed--only to discover that someone has fired up a leafblower nearby, drowning out everything the way radio static drowns out music.

As annoying as unwanted human noise is to us, it's devastating to other creatures. For example: if birds can't hear one another, they can't alert one another to approaching danger or attractive mates or good food sources. Prey animals can't hear predators in a noisy environment, which means more of them get eaten, affecting the ecological balance. Human noise pollution affects plant reproduction by scaring away birds that help distribute seeds, according to a recent paper in the Proceedings of the Royal Society of London B.

Rachel Buxton, an acoustic ecologist at Colorado State University, succinctly explains the essential problem with noise: “It really doesn’t have any boundaries.” Buxton and her colleagues reported recently in the journal Science that noise from humans at least doubles the background sound levels in most protected areas in the United States. “When we think about wilderness, we think about...going to see outstanding scenery,” says co-author Megan McKenna. “We really should think about soundscapes, too.”

Buxton and McKenna and their team used a model for predicting noise based on sound measurements taken all over the country by the National Park Service. Individual scientists hiked in to more than 400 listening stations to set up the equipment, each of which included a sound level meter and a recorder. Each recorder ran for 30 days, collecting every sound. The recordings were then analyzed by acoustic specialists. The researchers then constructed a model for predicting noise by figuring out which sounds were associated with geographic features such as elevation, annual rainfall, proximity to cities, highways and flight paths. By subtracting out natural sound sources, the scientists estimated the amount of noise pollution for each specific wilderness area.

The findings were mixed. Protected areas did show much lower levels of human-caused sound than the "buffer zones” of unprotected land near them, suggesting that these buffer zones really do insulate parks. But 63 percent of the protected areas showed an increase in sound levels of at least three decibels caused by noise pollution. Since decibels are logarithmic, three decibels indicates a doubling of background noise. More than a fifth of protected areas experienced 10 extra decibels of human noise. Sadly, the majority of areas considered “critical habitat” for endangered species were among the regions that dealt with the worst noise.

McKenna said that parks are taking steps to reduce human sounds, such as implementing shuttle systems to reduce the number of cars and posting library-style “quiet” signs. But the problem of pervasive traffic sound—all those low-frequency rumbles from ground and air—is not so easily solved. Buxton suggests that parks look into “quiet pavement” to muffle the sounds of rolling tires and establish noise corridors to align airplane flight paths with highways.

We here are Talkin' Birds plan to drive as little as possible in protected areas, opting instead for quieter transportation such as foot and bicycle. We'll try to keep our voices down, too. And we would never dream of playing a radio in the wilderness, not even to listen to our own show. We would rather not disturb the symphony of life around us, nor its musicians.

Think humans are the only creatures who can be sneaky? Think again: ravens can, too.

Imagining that others might have thoughts different from our own had been assumed to be a distinctly human ability. But new research from the University of Houston suggests that ravens can not only imagine what others are thinking but also change their own behavior according to what they imagine. Experts found that ravens hiding food were able to understand that they could be watched, even without seeing another bird, and behaved sneakily as a result.

Before you read on, you need to know that ravens hide food for later, a behavior called "caching." When they feed from an abundant source, they take some of the food with them and put it away, often in the ground, so they can return to it when times are lean.

Researchers placed a raven in a room adjacent to a room in which someone (um, a human) pretended to prepare food. These two rooms were joined by a window and a peephole.

When the window was closed and the peephole left open, the birds behaved as though they were being watched by a competitor: they hid their food quickly and did not return to a previous stash (which would reveal its location). When the peephole was closed, the ravens didn't hide food as quickly, and they'd use the stash multiple times. They would remain this unconcerned even when the researchers played raven sounds behind the closed peephole. In other words, the test ravens behaved differently only when conditions indicated that they were being watched.

This research matters because it demonstrates that ravens might be able to imagine what others are thinking. Until now, only animals closer to humans—such as chimps—had been shown to have this ability.

Professor Cameron Buckner, assistant professor of philosophy at the university, says the study gives important clues to the ability of animals to engage in abstract thought and indicates that we humans are not the only creatures who understand that others have a conscious mind.

Can't get enough Talkin' Birds? Good news! We're launching podcast-only "extras" to help tide you over.

Sometimes we have stories we'd love to share with you but that we just can't fit into the weekly broadcast. So now we're sharing them anyway—via podcast. How do you hear them? Easily.

1. If you already subscribe to our weekly show as a podcast, you'll receive these "extras" in your feed without any effort.

2. If you don't subscribe to our weekly show podcast, you can listen directly from our Archive. It's as easy as reading this blog. On our website, click "How to Listen," then "Archive." Scroll around (or simply search on "podcast"), click, and enjoy.

We here at Talkin' Birds seek to keep our listeners informed about developments in the world of birds and birding, so we've written this simple explanation of the Endangered Species Act and what makes it controversial. Why now? Because lawmakers in Washington, DC are going over it very carefully these days in order to decide what, if anything, should be changed about it. We ought to warn you: If you Google "Endangered Species Act of 1973," the top two results are strongly opinionated–in opposite ways. There's a lot of argument right now. Here, we hope, is a balanced picture.

The Endangered Species Act, or ESA, was signed into law in December 1973 by President Richard Nixon. Scientists had recognized for about a century that human activity was causing the extinction of fish, animals, and birds. While a few laws had been enacted to prevent over-hunting individual species (for instance, the American Bison), this law was the most comprehensive in that it intended to prevent and reverse extinction of all domestic endangered species, including maintaining and restoring their habitat. The Endangered Species Preservation Act of 1966 set the stage for the ESA by establishing a list of species in need of help. In 1969, the Act was emended to include species in danger of worldwide extinction. The ESA was and is more comprehensive in scope than both previous Acts.

We bird-lovers have probably heard how the Bald Eagle, the Whooping Crane, and the Peregrine Falcon, among others, have returned from the brink of extinction because of programs supported by the ESA. Millions of acres of habitat have been preserved; eggs have been incubated; chicks have grown up to reproduce successfully. Aside from birds, species from wolves to whales have been rescued so that each may continue to benefit its own ecosystem, not to mention the other species with which it interacts. (Every species that's saved is important to several others.) We have heard much about the good the ESA does.

But as successful as the ESA sounds, it is not without controversy. Some critics argue that, of the over 2000 species listed since 1973, fewer than 2% have recovered enough to come off the list. These critics feel that these numbers are proof that the ESA isn't helpful. Further, the ESA does not address the exotic pet trade within states. This means that, even though endangered species can't be sold internationally or even across state lines, they can be "donated" between states and even sold in the same state—which they feel means that those species really aren't being protected. But the most vocal critics of the ESA say that protecting habitat from human activity is, well, restrictive to humans. When it comes down to it, they argue, is the survival of a rare animal really more important than the use of its habitat to benefit human beings? Is, say, preserving a rare fish more valuable than providing drinking water for a community's children? This is a tough ethical question, and lawmakers have wrestled with it for decades. The mining and timber industries are hit particularly hard by ESA-based restrictions. In 1978, the ESA was emended to allow for species exemptions; these keep lawmakers arguing for months in states where a rare species risks being wiped out by industry.

This simplified explanation of the Endangered Species Act is only a start. If you'd like to learn more, we hope you'll check out these resources. We've tried to choose impartial ones, but, as we warned above, that's difficult. If you find any others you like, please let us know. As stewards of this planet and its inhabitants, let's keep one another in the loop.

We here at Talkin' Birds like to keep our listeners in the know about anything affecting birds. We've been hearing a lot in the news lately about Scott Pruitt, President Trump's nominee to head the EPA. However, we're not hearing much about the EPA itself, so we thought we'd explain what the EPA does.

EPA is the Environmental Protection Agency. (By the way, they don't use "the," so we'll stop too.) Their mission is to protect our health and environment, which they do in more areas of life than we had imagined. No fooling: If you check the A-Z index on their website, you'll see documents on everything from acid rain to the pesticide Worker Protection Standard. EPA researches, regulates, funds grants for, and provides information about pretty much anything having to do with the environment and human health in this country.

Environmental research:EPA has research stations throughout the United States. The scientists who work at them share findings with academic institutions, private sector agencies, and research agencies here and in other countries.

Regulation: When the United States Congress writes environmental laws, EPA writes regulations to enforce them. EPA then helps businesses and other organizations understand and comply with these regulations so they can obey the law.

Grants: EPA uses about half their funding to make grants to nonprofits, state programs, and educational institutions. These grants go to research and environmental cleanups, among other uses.

In case you're wondering EPA has done for birds, the answer is, "A lot." We bird-lovers are probably all familiar with such bird conservation initiatives as the North American Waterfowl Management Plan, established by EPA in 1986 and the Partners in Flight initiative to increase bird habitats in North and South America. EPA regulates use of pesticides; it was they who banned DDT in 1972 because of the harm it does to humans, wildlife, and especially birds. (In fact, EPA maintains a handy pesticide chemical database ) Then there's their data on birds and climate change: for starters, have a look at this page to see how bird wintering ranges have changed over the last fifty years. This short list above just scratches the surface how EPA benefits birds. If you'd like to see more, go to their website and search on "birds." You'll get 3,860 results. Again, no fooling.

So why is it important to think carefully about who is in charge of EPA? Because that person controls research, regulation, and information about so much that affects the life of all Americans--not just the human ones.

"Biodiversity" means "the variety of life in a particular habitat." Each life form, from bacterium to towering tree, plays a role in sustaining its ecosystem. Therefore, each life form matters.

There are few ecosystems on Earth with more biodiversity than a rainforest. A recent study shows that the loss of even a few species from that rainforest adversely affects its longevity. Although a forest may look healthy, if the creatures required for maintenance are missing, the forest can't regenerate if it's disturbed, and its trees will eventually die out.

Research from the Department of Life Sciences at Imperial College London, published in Proceedings of the Royal Society B, shows that intensive land use, such as for agriculture and ranching, often leads to the extinction of local forest birds. These birds perform "biodiversity services" that are necessary for maintaining the rainforest's health, such as keeping down the population of plant-eating insects and dispersing the seeds of tree species. But it isn't just the individual birds species that guarantee the future health of the forest, nor is it the number of species left alive; it's the way these species interact with other kinds of life.

The research team studied the composition of bird communities from 330 study sites in the Brazilian Amazon, sampling more than 450 bird species. They also kept track of what special traits these species possessed, such as their beak size and tail and wing shape. (These traits indicate what kind of job a species has evolved to do.) Then they looked at how landscape change affected these bird populations, specifically those birds who eat insects and those who disperse seeds.

The results were sobering. When insect-eating birds go locally extinct, leaf-eating insects can prevent young saplings from growing up into mature trees. When birds that eat certain seeds are missing, then the trees that grow from those seeds eventually go missing, too.

Dr Joseph Tobias, senior author of the study, says that land-use management policy can positively affect forest recovery. He suggests that a forest's ability to regenerate can be preserved, even if it's largely cleared, as long as patches of primary forest survive. “Our findings are a warning flag that we can’t just look at a snapshot of forest health as it appears now—we need to think about preserving the ecosystem processes that will allow forests to survive in the future.”

Next, the team plans to examine the impact of human activity on global ecosystems by using bird traits as a window onto the effects of environmental change.